 /*******************************************************************************
  * Copyright (c) 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  ******************************************************************************/

 package org.eclipse.ui.internal.services;

 import org.eclipse.jface.util.IPropertyChangeListener;

 /**
  * This is not meant to be implemented or extended by clients.
  *
  * @since 3.3
  *
  */
 public interface IEvaluationReference extends IEvaluationResultCache {
     public IPropertyChangeListener getListener();

     public String getProperty();

     /**
      * Sets whether or not the property change listener should be notified on
      * changes to the expression held by this result cache. Setting this to
      * <code>false</code> is useful for times in which you want to prevent flopping of the UI
      * on variable changes (ie: shell activation).
      *
      * @param evaluationEnabled
      */
     public void setPostingChanges(boolean evaluationEnabled);

     /**
      * Returns whether or not the property change listener should be notified on
      * changes to the expression held by this result cache. Setting this to
      * <code>false</code> is useful for times in which you want to prevent flopping of the UI
      * on variable changes (ie: shell activation).
      *
      * @return whether or not listeners should be notified at this time.
      */
     public boolean isPostingChanges();
     
     /**
      * Return an evaluation reference that could be impacted by changes to this
      * evaluation reference.
      *
      * @return the reference. May be <code>null</code>.
      */
     public IEvaluationReference getTargetReference();
     
     /**
      * Set an evaluation reference that could be impacted by changes to this
      * evaluation reference.
      *
      * @param ref the reference. May be <code>null</code>.
      */
     public void setTargetReference(IEvaluationReference ref);
 }

